Fluid-pressure motor



'March 22, 1927. E' G GARTIN FLUID PRESSURE MOTOR Filed July 11, 1921 2Sheets-Sheet 2 Patented Mar. 22, 1927.

UNETE@ STATES PA T ELMER Gr. GARTIN, OF CLAREMONT, NEVJ HAMPSHIRE,ASSIGNOR TO SULLIVAN MA- CHINERY COMPANY, A CORPORATION GFllIASSACHUSETTS.

FLUID-PRESSURE llOTOR.

Application filed July 11,

My invention relates to fluid pressure mo tors.

It has for its object to provide an improved fluid pressure motor. Afurther object of my invention is to provide an improved fluid pressuremotor which is adapted to be constructed in relatively large sizes andat the same time prevent undesirable vibration. A still further objectof my invention is to provide an improved fluid pressure motorpreferably of the percussive type in which vibration resulting fromchecking the nomentum of the piston upon the return sti-oke may bereduced to a minimum. A. still further object of my invention is toprovide an improved fluid pressure motor of the valveless percussivetype in which improved cushioning means for the return stroke will beprovided.

In the accoinpanying drawings I have shown, for purposes otillustratiom' three forms which my invention may assume in practice.

In these drawings e Fig. l is a diagrammatic view of one form of myimproved Construction, showing the piston about to begin its forwardstroke, the View being taken substantially on the broken section line1-1 of Fig. 6.

Fig. 2 is a similar view oi" the same form showing the parts with thepiston at the opposite end of its stroke.

Fig. 3 is a diagrammatic View of another form of my improvedconstruction, the pis-- ton being shown in the position corresponding toFig. 1.

Fig. 4 is a similar View of this second form, .showing the piston atapproximately the opposite end of its stroke.

Fig. 5 is a diagrammatic view of a third form which my invention mayassume in practice.

Fig. 6 is a transvcrse section on the line 6-6 of Fig. 1.

In the embodiment of my improved motor shown in Figures 1, 2, and 6 themotor comprses a cylinder 1 in which there reciprocates a pistongenerally indicated by 2 and having a striking bar 3 cooperating in awell known manner with a drill steel not shown. The piston 2 consists oftwo heads 4 and 5 connected by a reduced portion 7 about which there isformed an annular g'roove 6. The piston is bored out internally to forma supplemental cylinder 10 co- 1921. Serial No. &83,778.

aXial with the piston and with this cylinder a projection or piston 11attached to the rear head of the cylinder cooperates in a mannerhereinafter described.

Fluid is distributed to the opposite ends of the cylinder l andcontrolled in a manner similar to a well known commercial type of motor.Live fluid is supplied through a fiuidpressure supply passage 12 whichcommuncat'es at its forward end by means of a passage 13 of reduced areawith a storage chamber 14, and the fluid pressure supply passage 12 andstorage chamber 14': are respectively provided with ports 15 and 16longitudinally separated from each other by a slight distance andopening into the bore of the cylinder near the center thereof. Thesupply of fluid to the o-pposite ends of the cylinder is controlled bythe heads 4: and 5 and groove 6 of the piston, the groove 6 be- 7 ingadapted to alternately connect one or' both of the ports 15 and 16 withthe opposite ends of the cylinder in a manner hereinatter described. Thecylinder is likewise provided with suitable distribution passages 17 and18 leading from points adjacent the middle of the cylinder to theopposite ends thereof the passage 17 being provided with two supplyports 19 and 20, of which 19 constitutes a starting port, and at itsopposite 35 end communicating by means of a port 21 with the cylindernear its forward end. The passage 18 is provided with a supply port 22and with a distribution port 23, the latter being located in the extremerear end of ou the cylinder. Suitable eXhaust ports 8 and 9 are alsoprovided and .so disposed as to be uncovered by the opposite ends of thepiston at appropriate times.

Cooperating with the cylinder 10 formed :u in the piston andw'iththeprojection 11 secured to the rear head of cylinder 1 is a supply passage25 which extends centrally through the projection 11 and opens into thecylinder 10, this passage at its other o end being connected by means ofa pair of ports 26 and 27 with the bore of the cylinder, the passage 26being located in relatively the same cylinder belt as the port 22 andthe passage 27 being located somewhat 'further forward in the cylinder.It will be understood that the parts 10, 11, and ports 25, 26 and 27 andtheir spacial arrangement, both ;er se and in combination with theremainder of the Construction, form a part of my improvement in theabove mentioned well known commercial type of motor.

The operation of my improved motor is as follows: Starting with theparts in the position shown in Fig. 1, fluid pressure is beingtransmitted from the passage 12 by way of port 15 to the cylinder borewhere it is directed by the groove 6 formed in the piston to the port22- and thence by way of passage 18 and port 23 to the rear end of thecylinder where it acts on the annulus of the piston 2 surrounding theprojection ll. Fluid pressure is smultaneously admitted by way of port26 to passage 25, which conduots fluid into the cylinder chamber 10 inthe piston 2, where it acts upon the forward end of this cylinder andsupplements in eflect the pressure acting; on the rear end of thepiston. Under the combined action of the motive fluid in the rear end ofthe cylinder l and the cylnder 10, the piston moves forward and at, orabout mid-stroke, communication is closed between the port 15 and theport 22, after which further action of the pressure in the rear end ofthe cylinder 1 is expensive only. Substantially simultaneously with cutoff in the rear end of the cylinder, fluid pressure is admitted fromboth fluid pressure supply passage 12 and from storage chamber 14, thelatter of which was previously for a short time in communication withport 22, to port 19 and thence by way of passage 17 and port 21 to thefront end of the cylinder. At about the moment when port 15 is closed,port is opened and live fiuid flows by way of port- 16 out of storagechamber 14, supplemented in part by the stored pressure ther-ein, andpasses to the front end of the cylinder where it accumulates for thepurpose of making a return st-rok-e, and where it acts, when suf ficientpressure has been built up, to partially cushion the extreme end of theforward stroke, the latter effect, however, being only negligible duringdrilling operation of the motor, but becoming effective when the motoris being run idly and is not actlng on a drill; at which time the strokeis, of course, considerably longer as it is checked only by the cushion.Just before the end of said stroke, the communication of port 27 withthe fluid pressure supply is closed by its being overrun by the rearhead of the piston. It will accordingly be noted that live fluid hasacted for a considerably longer time, perhaps of the sti-oke, on theportion of the piston exposed to pressure in cylinder 10, whereby thepower of the st-rolce is increased and an earlier, but light, cushioningeifect on the rear stroke will be accomplished. Upon the return stroke,it will be noted that the port 27 Will be opened very much earlier thanis the port 22 and accordingly, as just stated, a much earlier partialcushioning efl'ect will be obtaincd, and even before the opening of theport 27 a cushioning effect to a lesser degree will be obtalned due tothe ,fact that the fluid pressure in cylinder 10 was only partiallyexpanded and will accordingly resist movement of the piston to someextent before live pressure is again admitted, this resistanc-eprogressively increasing due to the compression of the pressure in thecylinder 10 until the moment when a pressure equal to that of live fluidwill have again been reached. Throughout the remainder of the returnS-POl-G, live pressure will continue to act in the cylinder 10 tocushion and mor-e near-ly equalize the velocity of movement of thereturn pass of the piston. As a result of this construction, it will befound that greater forward speed will oifset slightly reduced returnspeed and the vibration of the niotor due to the sudden stoppng of themotion of a relatively heavy piston moving at a relatively high velocitywill be largely done away with. The location of the port 22, as a resultof `this construction, may be changed, of course, somewhat from itsposition in the commercial Construction heretofore mentioned, this portbeing moved somewhat further to the rear end of the cylinder andaccordngly the main cushioning action of the piston need not commence atquite so early a time in the stroke.

The modification shown in Fi'ures 3 and 4 isvery closely related in bothfunction and structure to that shown in Figures 1 and 2, the Chiefdifference being that I have provided an eXhaust port for the purpose ofpermitting the escape of the fluid which has been actiug in the eylinder10 therefrom at approxin'ately the forward limit of the piston stroke,the purpose of this eXhaust being to permit the starting of the pistonon its return travel with no pressure acting to re- V sist its motion.In this Construction the passage 25' is made larger than was thepassage' 25 for a considerable portion of its length and communicateswith the cylinder bore l at three longitudinally separated pointsinstead of at two. The ports 26' and 27' are located at substantiallythe same positions as were the ports 26 and 27, but an additionalpassage is provided which is so located as to be uncovered by the rearend of the piston head t at or preferably just after the momen! when theexhaust port for the rcar end of the cylindcr is uncovered. At this timethe ports 26' and 27' are both closed and accordingl there is no loss oflive fluid by direct passage from the inlet to the exhaust, but suchfluid as is stored in the cylinoer 10 and in the various passages isfree to pass out through the exhaust port. The passagjes 25 and 27 andthe forward portion of the passage 25' which is for-med in the cylinderwall is of' less diameter than is lili) the remainderof the passage,this being for the purposes of controlling the fluid pressure supply Ioythe port areas of the connections 26' and 27' while providing ample areafor the haust port.

The op tion is, in the general details of` fluid distribution to theopposite ends of the cylinder l, the same in the first form, but thecylinder lt) is exhausted at the forward end of the piston stroke andaccordingly the initial motion ot the piston on its return Stroke is notcushioned and so a slightly quiclter start can be obtained.

In Figure 5 I have shown a still further form of my invention and onewhich is simpler than either of' those previously described. In thiscase the passage 27 is entirely omi ted and no exhaust port is providedtor the cylinder 10, the port 26" being closed substantially at the sametime as the port 22. The operation inthis case is that the fluidentrapped in the chamber 10 at the moment of closure of port 26 actsexpansively thei-ein during the remainder of the sti-oke and thereafteris recompressed up to initial pressure until the time when the port 26"is reopened. In this case I rely upon the recompression of the expanoledfluid to provide the equalization by the slight initial retardation ofthe piston, this construction, however, difl'ering from the previous-lydescribed Construction of Figures 3 and l in that, instead of exhaustingand resupplying the fluid, I obtain the same low pressure effect in thebeginning of the stroke by a considerable degree of expansion in thecntrapped fluid and thereafter recompress the same instead ofreadmitting a supply of fluid.

in all the forms of my invcntion herein shown for purposes ofillustration, the common feature is the provision of means acting toaccelerate the velocity during the forward strole and to slightlyadvance the beginning of cushioning on the return stroke whereby thepiston does not acquire so extreme a veloeity toward the middle of itsreturn stroke and according-ly such a great reaction upon the stoppingof the piston at the end of the roke is not required. Accordingly., the(sc-.1118 e'flfect can be obtained in the matter of power and speed ofoperation by setting back the admission port for the rear end of thecylinder a slight distance toward the rear end of the cylinder and arelatively vibrationiess motor may be obtaned.

While I have in this application specifically described three formswhich my invention may assume in practice, it will be understood thatthese forms of the same are shown for purposes of illustration' and thatthe invention may be modified and embodied in other forms Withoutdepartng from its spirit or the scope of the appended claims.

ation of this form of my inven- What I claim as new and desire to secureby Letters Patent is:

1. In a fluid pressure drilling motor, the combination with, a cylinder,a piston therein, and means for dstributing fluid under pressurealternately to the opposite ends thereof and for exhausting used fluid,of fluid cushioning means controlled by said piston' for subjecting aportion thereof to fluid pressure resisting the rearward movementthereof, before the moment when the first mentioned fluid distributingmeans for the rear end of said cylinder is operative.

2. In a fluid pressure drilling motor, the combination with a cylinder apiston therein, and means for distributing fluid under pressurealternately to the opposite encls thereof and for exhausting used fluid,of fluid cushioning means cooperating with said piston for subjecting aportion thereof intermittently to fluid pressure for resistng rearwardmovement of said piston, before the moment when the first mentionedfluid distributing means for the rear end of said cylinder is operative.

3. In a fluid pressure drilling` motor, the combination, w'ith acylinder, a piston reciprocable therein, and piston controlled means fordistributing fluid pressure alternately to the front and rear ends ofthe cylinder and for the exhaust of used fluid therefrom, of fluidcushioning means for subjecting a portion of said piston to fluidpressure for substantially the entire rearward stroke of said piston tooppose rearward movement thereof. said piston controlled means being`operable independently of said latter means.

4. In a fluid pressure drilling motor, the combination with a cylinder,a piston reciprocable therein, and piston controlled means fordistributing fluid pressure alternately to the front and rear ends ofthe cylinder and for the exhaust of used fluid therefrom, ,of fluidcushioning means for subjecting a portion of said piston to fluidpressure for substantially the entire rearward stroke of said piston tooppose rear-ward movement thereof, said meansbeing operative to providea pressure less than the inlet pressure to resist return motion'of saidpiston at the beginning of the rearward pass of said piston.

5. In a fluid pressure drlling motor, the combination with a cylinder apiston therein, means for distributing fluid under pressure to theopposite ends thereof for a portion of the strokes in each direction,and means for eXhaust-ing used fluid, of fluid cushioning meanscomprising a projection fixed to one of said first mentioned elementsand a cylinder formed in the other together with means for supplyingfluid pressure thereto, said projection and cylinder always having asubstantially non-leak fit, to control the velocity of the piston duringthe return stroke of the piston.

(3. In a fluid pressure drilling motor, a cylnder, a piston therem,means for distributing fluid under pressure to the opposite ends thereoffor a portion of the strokes in each direction, means for exhaustingused fluid, and means comprising a projection fixed to said cylinder anda cylnder formed insad piston together withmeans for supplying fluidpressure thereto, to control the velocity of the piston during thereturn stroke of the piston, fluid flow to said opposite ends beingefl'ected independently of said latter fluid flow.

7. In a fluid pressure drillinp; motor, a cylinder, a piston thei-ein,means for distributing fluid under pressure alternately to the oppositeends thereof and exhausting used fluid therefrom, said distributingmeans heing operative to supply fluid to each end of said cylinderprio-r to the completion of the stroke toward that end, and meanscomprising a cylinder formed in one of said first mentioned elements anda projecton secured to the other thereof, together With means forperiodically admitting fluid to said latter cylinder prior to theadmission of fluid to the end of said first mentioned cylinder adjacentwhich said second mentioned cylinder and projection are arranged,Whereby to regulate the velocitv of the stroke toward that end of thecylinder.

8. In a fluid pressnre drilling motor, a cylinder, a piston reciprocahletherein, means for distributing' fluid under pressure to the oppositeends thereof and exhausting used fluid therefrom, and means controlledby the piston to admit intermittentlv fluid pressure to a portion of thepiston during its rear- Ward movement.

9. (In a fluid pressure drilling motor, a eylinder, a piston recprocabletherein, fluid supply means, piston controlled means for distrihuting'fluid pressure alternately to and from the rear ends of the cylinder andfor the exhaust of used fluid therefrom, and means for subjecting aportion of said piston to fluid pressure for only substantially theentire rearWard stroke of said piston to oppose rearward movementthereot.

10. In a fluid pressure drilling motor. a cylnder, a pistonreciprocable' therein, means for distributinn fluid under pressure tothe opposite ends thereoi" and exhausting' used fluid therei rom. andmeans controlled by the piston to admit fluid within said piston duringonly a portion ot the cycle of movement of said piston to resistrearward movement and to assist forward movement of said piston. r

11. In a fluid pressure drilling motor a cylinder, a pistonreciprocalole therein, fluid pressure distributing means to supplypressure alternatelv to the opposite ends ot the cylinder and to eXhaustused fluid therefrom and means arranged concentrically within the pistonand separate from the fluid distributing means to control the velocityof said piston by exerting a varying :force on said piston.

12. In a fluid pressure drilling motor, a cylinder, a pistonreciprocable therein, means 'for distributing fluid under pressurealternately to the opposite ends thereof and eX- hausting used fluidtherefrom, said distributing means being operative to supply fluid toeach end of said cylinder prior to the completion ox" the stroke towardthat end, and means comprisng a cylinder having a bore ot' uniformdimensions formed in one of said first mentioned elements and a pistonconstituting memher Secured to the other thereot' and having acontinuous running fit in said bore, a ported passage leading theretoand means controlled by said motor piston to close said port at apredetermined point in the travel of the piston.

13. In a fluid pressure drilling motor, a cylinder, a pistonreciprocable thercin, an inlet port, means tor distributing fluid underpressure to the opposite ends of the cylinder and exhausting fluidtherefrom, and means ?tor intermittently sulojecting a portion of thepiston to fluid pressure resisting the rearward movement thereof beforethe instant When the first mentioned fluid distributing means for therear end of said cylinder is operative. i

' 14. In a fluid pressure drilling motor, a cylinder, a pistonreciprocable therein, fluid pressure means for cushioning the rearwardstroke of said piston, and means for supplying actuating fluid toopposite ends of said piston operable independently of fluid flow tosaid other means.

15. ,in a fluid pressure drilling motor, a plurality of relatively smalland large piston and cylinder elements, one of which is disposed at therear of the other, means for supplying fluid to opposite ends of thelarger cylinder. and means for supplying live pressure fluidintermittently to said smaller cylinder.

16. In a fluid pressure drilline motor` a plurality of relatively smalland large piston and cylinder elements. one ot which is disposed at therear end of the other, means for suppl vinz fluid to opposite ends ofthe larger cylinder. and means for supplying intermittently fluid underpressure above atmosphere to said smaller cylinder upon the rearwardstroke of said piston.

17. In a fluid pressure drilling motor, a plurality of sets of pistonand cvlinder elements, meansfwherebv fluid may be supplied to act on oneof said pistons to eflect fluid cushioning of said other piston, andmeans for exhaustin said cushioning fluid.

18. In a flud pressure drilling motor, the combination With a cylinderand a piston recprocable therein having a cylindrical bore,

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of fluid eushioning means for said piston comprising a piston extendingwithin said bore, and means 'or supplying fluid to said bore andexhausting it therefrom.

19. In a fluid pressure drlling motor, a cylinder, a piston reciprocabletherein having a, cylindrical bore, a piston extending within said bore,and means for supplying fluid to said bore and exhausting it therefrom,said means including a. common passage.

20. In a, fluid pressure drilling` motor, a cylinder, a pistonrecprocable therein having a cylindrical bore, a. piston extendingwithin said bore, and means for supplying fluid to said bore andexhausting it therefrom, said means including a common passage andbranch passages.

21. In a fluid pressure drilling motor, a cylinder, e pistonreciprocable thencin having a cylindrical bore, a piston ext'endingwithin said bore, and means for supplying fluid to said bore andexhausting it therefrom, said means including a common passage andbranch passages adapted respectively to conduct live fluid and exhaustfluid.

22. In a fluid pressure drilling motor, a cylinder, a pistonreciprocable therein having a cylindrical bore, a piston extendingwithin said bore, and means for supplyng fluid to said bore andexhausting it therefrom, said means including a common passagecontrolled by said reciprocable pston.

In testimony whereof I afiix my signature.

ELMER G. GARTIN.

